特厚煤层上部远距离解放层开采卸压效果研究

Research on the decompression effect of long-distance liberation seam mining in the upper part of extra thick coal

开采解放层是消除冲击地压的一项区域性根本措施。针对矿井局部可采3煤层开采对其下方50~70 m主采5煤层工作面应力分布影响问题,采用数值模拟方法进行分析研究,研究结果表明:作为解放层的3煤层130101工作面回采会对其正下方煤体产生明显的卸压作用,但同时加剧下方周围岩体中煤(岩)应力集中,积聚大量弹性能,形成冲击地压显现的能量条件;解放层布置时应能够对被解放层充分覆盖,避免因解放层范围过小,在其边缘地带形成新的应力增高区,不能充分发挥解放层作用。130101工作面下部5煤层250208上工作面开采时,在应力增高区域采用顶板爆破卸压解危技术弱化顶板强度,形成缓冲阻隔带,降低巷道周围应力集中,取得了良好的卸压效果,保证了工作面安全回采。

Mining liberated layers is a fundamental regional measure to eliminate rock bursts.Aiming at the influence of the mining of partially mineable No.3 coal seams on the stress distribution of the main mining No.5 coal seam working face of 50~70 m below,numerical simulation methods were used to analyze and research.The research results showed that the mining of the No.3 coal seam 130101 working face as a liberated layer would be effective the coal mass directly below it produced obvious pressure relief,but at the same time it intensified the stress concentration of coal(rock)in the surrounding rock mass below it,accumulated a large amount of elastic energy,and formed the energy condition for the appearance of rock burst;when the liberation layer was arranged,it should be able to relieve the liberated the layer was fully covered to avoid the formation of a new stress-increasing area on the edge of the liberation layer due to the too small scope of the liberation layer,and the liberation layer could not fully play its role.When mining in the lower part of the 130101 working face in the 5 coal seam 250208 upper working face,the roof blasting pressure relief technology was used in the stress-increasing area to weaken the roof strength,formed a buffer barrier zone,reduced the stress concentration around the roadway,and achieved a good pressure relief effect to ensure the working face Safe stoping.